The present invention pertains to a control unit for setting heating, air conditioning, and/or ventilation in motor vehicles, and particularly to such a unit that can be inserted into the instrument panel or dashboard of the vehicle.
Such control units, which can be installed in the instrument panel of a motor vehicle, are used, among other things, for opening the distributor flaps of outlets for cool or warm air to varying extents as desired. They are controlled usually via so-called Bowden cables.
A control unit for opening and closing the air control flaps of heating and air conditioning units of motor vehicles is described in German patent publication No. 1,129,388, in which there is disclosed two adjusting levers which are movable in slots provided in the instrument panel. The degree of ventilation and heat is set by means of the adjusting levers, while the flow of heating medium to the heat exchanger is controlled with a control knob. The first adjusting lever, which controls the fresh air supply, receives a larger portion of the fresh air only after the adjusting lever of the zone flap has been shifted by a considerable extent. The amount of fresh air decreases considerably when the adjusting lever controlling the fresh air supply is shifted over the first half of its regulating range. The second adjusting lever is used to control the top and bottom vents in the interior of the automobile. Therefore, starting from the closed position, the control flaps perform a progressively increasing opening movement. This is achieved in that the adjusting lever is provided with leg ends with different lengths. The adjusting lever is movable by means of an oblong slot through which a fixed pin extends in the direction of the longitudinal axis of the oblong slot. The lever is also rotatable around the pin at the same time. A Bowden cable is attached to the short end of the leg. This end of the adjusting level describes a curve in the form of a parabola. The other adjusting lever also operates the flap with a slightly progressively increasing opening path.
Another mechanism for adjusting several functions of an air conditioner in a motor vehicle by means of a single adjusting lever is known from German patent publication No. 27 21 497. A T-shaped adjusting lever reaches through an adjusting slot and the two lateral legs are linked in two axes of rotation on two knuckle arms. Each of these knuckle arms is linked around a fixed axis of rotation. In addition, a guide groove is provided in each knuckle arm for adjusting a control lever. These control levers are in turn pivoted around fixed axes of rotation. They are adjusted by guiding one cross pin each, attached to the control lever in the guide grooves. Bowden cables are attached to the free ends of the control levers.
Another device for controlling Bowden cables by means of a control knob, in which a flexible pulling and pressing member is arranged in a casing, is disclosed in German patent publication No. 24 05 321. This member is located on a cylindrical disk pivoted in the casing, which disk is connected with the control knob via a carrier. One end of the member is attached to the disk, while a Bowden cable is attached to the other end. In addition, the member is guided in a travel-limiting tube. This tube can be arranged in such a way that the Bowden cable is led away from the casing in an angular or arc-shaped pattern. It is also possible to actuate a plurality of flexible pulling and pressing members with the same control knob. The corresponding cylindrical disks have different diameters, so that different adjustment path lengths can be obtained.
A control knob for controlling a Bowden cable is provided in the control unit according to German patent publication No. 31 04 482. The Bowden cable is connected to a disk or drum via a flexible pulling and pressing member. Over part of its circumference, the drum has a toothed rim whose teeth mesh with the teeth of the member.
According to the latter two disclosures, the Bowden cables being actuated are led away in tangential direction relative to the disk or drum. However, there are also cases in which the Bowden cables must run parallel to the axis of rotation of the control knob. One mechanism to affect this is shown in German patent publication No. 31 36 672. A threaded drum is rotated by the control knob. Parallel to the drum is a double guide. A slide which meshes with the thread of the drum via a sliding pin is carried during the rotation of the drum and slides on the guide. The threads may have uniform or different pitches. A fastening means for the Bowden cable is provided as the sliding pin proper.
A control unit is also known which uses bevel gears to actuate Bowden cables. A control knob is rotatably mounted on the front panel of a body. A first bevel gear is connected with the control knob. Behind the front panel is located a rear carrier member in the form of a frame. A two-armed, one-piece, flat and plate-shaped lever is rotatably mounted in this frame; one arm of this lever has a circular segment on one side whose teeth mesh with the teeth of the first bevel gear and thus acts as a second bevel gear. A Bowden cable is attached to the free end of the other arm. Since the lever is a one-piece lever, only linear movement of the Bowden cable is possible. In addition, it is not possible to make the control knob continuously rotatable.
The objective of the present invention is to provide a control unit of the type described in the introduction using simple means in such a way that one or more Bowden cables, extending parallel to the direction of the axis of rotation of the control knob, can be actuated with one control knob with either limited or unlimited turning range, the Bowden cables having both linear and nonlinear adjustment paths which are independent of each other.